spec: clarified handling of empty pathWhitelist directories
spec: clarified handling of empty pathWhitelist directories

Wording as suggested by @jonboulle.

craimbert/spec,endocode/appc-spec,iaguis/appc-spec,appc/spec,yifan-gu/spec,krnowak/appc-spec,endocode/appc-spec,marineam/spec,ChengTiesheng/spec,iaguis/appc-spec,jonboulle/spec,ChengTiesheng/spec,squeed/spec,yifan-gu/spec,alban/appc-spec,zenlinTechnofreak/spec,3ofcoins/appc-spec,marineam/spec,squeed/spec,apcera/appc-spec,iaguis/appc-spec,krnowak/appc-spec,squeed/spec,craimbert/spec,yifan-gu/spec,apcera/appc-spec,alban/appc-spec,zenlinTechnofreak/spec,marineam/spec,apcera/appc-spec,dgonyeo/spec,krnowak/appc-spec,3ofcoins/appc-spec,3ofcoins/appc-spec,jonboulle/spec,stufflebear/spec,zenlinTechnofreak/spec,stufflebear/spec,appc/spec,ChengTiesheng/spec,craimbert/spec,stufflebear/spec,tklauser/spec,endocode/appc-spec,alban/appc-spec,dgonyeo/spec,dustymabe/spec,tklauser/spec,dgonyeo/spec,tklauser/spec,appc/spec,jonboulle/spec,dustymabe/spec,dustymabe/spec